1. Field of Invention
The invention relates generally to compositions for use as insect attractants/repellents and, more particularly, the insect specific control of economically important pests.
2. Description of Related Art
Insect pests are known to cause huge economic losses in agriculture. Certain infestations can decimate entire crop yields which can exert detrimental effects on entire economies. Fruit flies, which belong to the family of tephritidae, cause severe losses on many fruit trees including olive, citrus, peach, pear, fig, apricot and avocado. As a result, various methods of pest control have been developed to reduce such losses. Administration of toxic pesticides over large areas, while effective to reduce the number of pests, raises environmental concerns and can result in toxicity to consumers of fruit. Consequently, techniques which reduce or eliminate the negative environmental impact of pest control are highly desirable.
One strategy is to provide an insect lure which attracts and traps insects in the vicinity to allow a determination of exactly what insects are in the vicinity. In this manner, effective treatments may be devised for specific pests which are specific to those pests thus increasing the efficiency of pest control. Many field applications of lures use baited-traps and paintable sticky adhesives. See Epsky et al., Environ. Entomol., 20:1680-1686 (1995); Heath et al., Florida Entomologist 79:144-153 (1996). In addition, an insect lure may be mixed with a pesticide such that insects are attracted to and come into contact with the pesticide, resulting in pest control. This technique avoids widespread dissemination of pesticides on fruits and crops.
Several protein hydrolysates, fruit juices, and synthetic chemicals have been reported to attract flies belonging the tephritidae family. See, e.g., Robacker, D. C., Environ. Entomol. 20:1680-1686 (1991); Epsky et al., Environ. Entomol. 24:1387-1395 (1995); Cirio et al., Bolletino del Laboratorio di Entomologia Agraria "Filipo Silvestri", Portici 37:127-139 (1980). Examples of synthetic chemicals which attract fruit flies include trimedlure (1,1 di methyl-4 (and 5)-chloro-2-methyl-cyclohexane-l-carboxylate) and ionone- and ionol-related compounds, but the activity of the latter two compounds is specific to males. See Flath et al. J. Econ. Entomol. 87:1470-1476 (1994).
Certain commercially available protein hydrolysates, such as yeast hydrolysate and corn hydrolysate, are used as fruit fly attractants and are generally produced by acid hydrolysis or by enzymatic hydrolysis with trypsin. Protein hydrolysates provide a source of energy for flies, especially for females due to extra protein needed to mature their ova (Nigg et al., Age-related response of Anastrepha suspensa (Diptera:Tephritidae) to protein hydrolysate and sucrose, J. Econ. Entomol. 88:669-677 (1995). Solutions of ammonium salts and animal excrements as well as mixtures of various ammonium salts and commercial hydrolysates have also been reported to attract fruit flies. See Reissig, W. H., J. Econ. Entomol. 67:484-486 (1974); Reissig, W. H., J. Econ. Entomol. 69:6639-643 (1976); Propky et al. Environ. Entomol. 22:453-458 (1993); Epsky et al., Environ. Entomol. 20:1680-1686 (1995); Nigg et al. (1995), supra. NU-LURE.TM., is a commercially available standard lure made of corn protein hydrolysate, which has been used to trap flies belonging to Tephritidae. See Banham, F. L., J. Entomol. Soc. British Columbia 70:13-16 (1973); Loke et al., Pest Management and the Environment in 2000, H. S. Barlow, Ed., CAB International, Wallingford, U.K., 111-126 (1992); Flath et al., 1994 supra; Nigg et al. 1995 supra; Heath et al. 1996 supra. However, NU-LURE.TM. acts as a general attractant and lacks specificity against flies belonging to Tephritidae family. See Heath et al., supra.
Soy hydrolysates produced by acid hydrolysis are reported to have been used as attractants. A soy hydrolysate was reported to have limited activity as an attractant when used alone in Sectar traps, and was active only in the presence of 50% ammonium hydroxide (Reissig, J. Econ. Entomol. 67:484-486 (1974) Table 1; Reissig, J. Econ. Entomol. 69:639-643 (1976). Other studies indicate that acid hydrolyzed or trypsin digested soy extracts alone (i.e. without addition of 50% ammonium acetate) do not have sufficient activity to attract fruit flies. See Reissig, (1976) supra; Banham, supra; Reissig, (1974) supra. Soy lecithin and its chemical fractions are reported to have repellent activity against fruit flies belonging to Tephritidae (Cirio et al., supra). U.S. Pat. No. 4,160,824 describes insect attractive compositions containing acid-hydrolyzed defatted cereals which is indicated to be a more effective insect attractant than known acid-hydrolyzed soy bean cakes.
Existing protein hydrolysate lures are relatively expensive and are unsuited in economically depressed areas. There is a clear need for economic commercially available lures which have sufficient activity and target specific pests.